Score a big one for Massachusetts. The state has the third-lowest obesity rate in the nation — behind fitness-obsessed Colorado and surfing-weather-all-year-round Hawaii, according to 2011 data issued last week by the US Centers for Disease Control and Prevention. In previous years, the state ranked lower compared with other states such as Connecticut.

The state’s obesity rate for 2011 — 22.7 percent — is nearly one percentage point lower than in 2010 and nearly one percentage point higher than in 2009. But that may not be indicative of any real changes in obesity levels. The CDC tweaked the survey’s methodology this year to get a more accurate reading.